Uploading a modified ControlLogix project from PLC to an old .acd file

On my laptop I have an old.acd file with important comments in it. The file was modified and downloaded to my AB-1756 long time ago.


Later a few functional blocks were added to the program in the AB-1756 without saving the .acd file.



Now I would like to upload the program from the PLC to the old.acd file. I need that old important comments to be saved.



Will the Logix5000 keep the old comments unchanged in the old.acd file after uploading the modified program?

That's actually a really good question....
I know the old RSLogix 5/500 software would give you the option to upload and merge the uploaded code with the existing comment/symbol database. I don't remember seeing that option in RSLogix 5000.


Have you tried to go online with the offline copy? Sometimes, it gives you the opportunity to correlate changes but that may have been added in later versions. I don't remember if I saw that in v16 (newest version that supports the 1756-L55). And it doesn't work if the changes are extensive.



RSLogix 5000 does have an option to export the tags and logic comments into CSV. I'd first upload the project from the PLC and then do an export from the offline file (Tools -> Export, select CSV file type and select All tags and All logic comments). Then import that into the uploaded project file. See if you get everything and if it will still go online.

Another way:
Offline
I think you can import that old project into your present version you have on your laptop. Rename it so you can view it and see your comments there.

Thank you joseph_e2.
Thank you Jim3846.
Export Tags and Comments is a useful feature.
I did not know about it. In offline mode it works fast and seamless. Before your answers I really was going to read the old comments from the old.acd file and retype them to the uploaded new file by my hands.
Knowing about this feature now I am going to compare the .xls files exported from old .acd copies with programs that currently are running in our PLCs.

the question is whether the last programmer changed or deleted your comments when he modified the program.

i would make a copy of your old file as a safety backup and put it in a location on the pc away from the plc software. then open your file and go online, if it says upload, upload the program and see if your comments are there. if they are, Great. if everything is missing, you still have your backup copy and will have to look at the program to see if the comments are still valid. if so, copy and paste.
james

Thank you James. Your answer has helped me to formulate one more question.
If the last programmer made little changes to some rungs (or added some FBs or links between them in subroutines) and if I open my old file, go online and upload the program then will Logix5000 align new logic from the plc memory and my old comments from my file correctly? Will they match?